Structural basis for the inhibition of voltage-dependent K+ channel by gating modifier toxin

Shin Ichiro Ozawa, Tomomi Kimura, Tomohiro Nozaki, Hitomi Harada, Ichio Shimada, Masanori Osawa

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Voltage-dependent K+ (Kv) channels play crucial roles in nerve and muscle action potentials. Voltagesensing domains (VSDs) of Kv channels sense changes in the transmembrane potential, regulating the K+-permeability across the membrane. Gating modifier toxins, which have been used for the functional analyses of Kv channels, inhibit Kv channels by binding to VSD. However, the structural basis for the inhibition remains elusive. Here, fluorescence and NMR analyses of the interaction between VSD derived from KvAP channel and its gating modifier toxin, VSTx1, indicate that VSTx1 recognizes VSD under depolarized condition. We identified the VSD-binding residues of VSTx1 and their proximal residues of VSD by the cross-saturation (CS) and amino acid selective CS experiments, which enabled to build a docking model of the complex. These results provide structural basis for the specific binding and inhibition of Kv channels by gating modifier toxins.

Original languageEnglish
Article number14226
JournalScientific Reports
Volume5
DOIs
Publication statusPublished - 2015 Sep 18

ASJC Scopus subject areas

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